Communication between two or more users employing electronic mail (e-mail) over a public network, such as the “World Wide Web” or a local-area network (LAN) is well known. A piece of e-mail typically includes a short message or piece of text, and, optionally, one or more larger files attached to the e-mail. Frequently, a user sends a copy of an e-mail both to one or more primary recipients (specified in the “To:” field) and to other secondary, or “carbon copy” recipients (specified in the “cc:” field). Recipients of the e-mail typically see a list naming each of the other direct and carbon-copy recipients of the e-mail. A piece of e-mail which is forwarded and cc'd a number of times before reaching a recipient typically includes the entire propagation history of the e-mail, starting from its original sender, unless this history is deliberately deleted by a user at some point in the propagation of the e-mail.
Systems which parse electronic mail in order to differentiate between the different fields are known. U.S. Pat. No. 5,948,058 to Kudoh et al., which is incorporated herein by reference, describes a method and apparatus for cataloging and retrieving e-mail. Header information and a defined class of every e-mail are displayed simultaneously so as to enable a user's e-mails to be categorized more efficiently. Each category may have its own symbol or icon to enable simple visual categorization.
U.S. Pat. No. 5,544,360 to Lewak et al., which is incorporated herein by reference, describes a computer filing system for accessing computer files and data according to user-designated criteria.